<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .box {
        width: 50%;
        height: 200px;
        padding: 1px;
        border: 1px solid;
        background-color: #f00;
        /* float: left; */
        box-sizing: border-box;
        box-shadow: 9px 10px 9px 4px black;
      }

      h1 {
        text-align: center;
        text-shadow: 1px 2px 4px red;
      }
    </style>
  </head>
  <body>
    <div class="box"></div>
    <!-- <div class="box"></div> -->

    <h1>好好学习，天天向上</h1>
  </body>
</html>
